The use of mineral oil compositions containing a polyethylene polymer of specific properties in the formation of cable filler compositions has been described, for example in U.S. Pat. Nos. 4,176,240 and 3,879,575. As described in U.S. Pat. No. 4,176,240, the contents of which are incorporated by reference herein, compositions for use as filling material can be prepared by admixing mineral oil, a styrene-ethylene butylene-styrene block copolymer, and a polyethylene which has a softening point of between 110.degree.-130.degree. C. Such compositions have been found to have improved handling characteristics over petroleum jelly-polyethylene cable filling materials.
It has now been found that a cable filling composition having excellent properties may be formed by admixing mineral oil, a styrene-ethylene butylene-styrene block copolymer and an isotactic, crystalline polypropylene polymer having an average molecular weight of between 20,000 and 50,000.